Pumping apparatus



Aug. 9, 1949. s :05 2,478,568

PUMPING APPARATUS 2 Sheets-Sheet 1 Filed March 8, 1946 FIE 'L v T] r i a W W 44 E l 36, i 46 E 42- 35 32 2 4 2 r g 38 25' E 7 "7/ 39 LLB-37 LLJJ-57 0) (O 74 L (O &

5.3 E 1: 1 9 2o 23 A 4 INVENTOR. Harrison 5. Caz

A TTORNE v Aug. 9, 1949. H. s COE PUMPING APPARATUS Filed .March 8, 1946 2 Sheets-Sheet 2 IVENTOR. x fiarr/spn 5. 60 BY ATTORNEY Patented Aug. 9 949 UNITED STATES PATENT OFFICE 2,478,568 PUMPING APPARATUS Harrison S. Coe, Palo Alto, Calif. Application March 8, 1946, Serial No. 652,978

9 Claims. 7 (01.103-44) This invention relates to pumping apparatus of the type in which a diaphragm, actuated by recurrent impulses of suction and pressure, im-

parted by a plunger actingagainst an impelling.

liquid in an impelling liquid chamber, causes a pumping compartment which is separated by the diaphragm from said impelling liquid chamber, to alternately expand and contract in the process of pumping, generally as shown in my co-pending application Serial No. 608,850 filed August 4, 1945,

novel means whereby, if the diaphragm becomes so displaced, while the pump is idle, it will, when the pump is started, be drawn into its normal locus of oscillation.

Another object of my invention is to provide novel means adapted to be employed in adjusting the capacity at which the pump is operated. Generally speaking, my invention consists of means adapted to prevent excessive introduction of liquid and to cause the admission of air into i the impelling liquid chambers of the pump when f the pumping compartment contracts during periods of idleness, and means adapted to permit the expulsion of said air during the starting of'the pump and, thereafter, of preventing or controlling the admission of such air into said compartment during periods when the pump is in operation. Y

Other objects and advantages will appear from the following specification and drawings in which:

Figure l is a vertical sectional View of a diaphragm pump of the type described illustrating the form and position of a mechanism adapted to establish the zone of oscillation of the diaphragm and ofv elements adapted to function in my invention.

Figure 2 is a detailed vertical side elevation partly in section of means mounted on the pump shown in Figure 1 and adapted to function with Figure 3 is a side elevation of the assembly shown in Figure 2.

. As shown in Figure 1 a cylindrical member! and peripherally extending plate members I l and I2 enclose a chamber 13, of which members ll all) the present invention and in stabilizing the zone of oscillation of the diaphragm.

V and [2 form, respectively, the upper and lower walls, and in which is incorporated a pumping or impelled liquid compartment M, which is separated from the impelling liquid chamber l3 by a tubular diaphragm l5.

Diaphragm l5 may be of rubber or other pliable material and preferably has a relatively thick lower section, a thinner central section of greater diameter when open than has either end section and a smaller bore at its upper or outlet end.

Lower wall l2 of chamber I3 is provided with an inwardly flaring orifice which is adapted to receive a tubular gasket 2| and the lower portion 22 of tubular cage-like member 23. Lower wall portion 22 is tapered in such a manner that it cooperates with the wall of orifice 20 to provide a wedging effect whereby a'leak proof seal there between is obtained. The upper end 24 of member 23 is provided with a peripheral flange 25 which is adapted to cooperate with wall ll of chamber I3 and to be secured in leak proof contact therewith by screws 26 and gasket 21. The upper portion 24 and the lower portion 22 of member 23 are rigidly connected by spacing members 28 which are of a length adapted to cause the wedging efiect of portion 22 in orifice 20 as required to compress gasket 2|.

I have also provided an open tubular member 30 flanged at its upper end and provided with orifices 3| opposite'the open areas 29 between spacing members 28 in member 23 with its flange 32 resting on the upper surface of annular flange 25. Diaphragm H5 is adapted for mounting at its lower and upper ends and is held in impervious contact with the outer surfaces 34 and 35 of portions 22 and 24 respectively of cage member 23. In mounted position, diaphragm I5 encloses pumping compartment I4 and tubular member 30 extends downwardly, co-axially, within it from the outlet end of said compartment.

Plate member II in conjunction with casing 36, which is secured in sealed contact therewith by means of bolts 37 and gasket 38, constitutes a valve case 39, in which is mounted an outlet valve assembly 40 which is adapted to conduct fluid being expelled from compartment M to a discharge pipe 4 I Valve 40 is adapted to prevent a counterflow of fluid from pipe 4| to compartment [4.

The upper wall of case 39 is provided with a circular'aperture 42 which is co-axially aligned with tubular member 30' and cylindrical member ID. A cover plate 43 is adapted to close aperture 42 and a liquid proof contact between casing 39 and plate 43 is securedbyzmeansof a gasket 44 and bolt 45. The lower inner wall of cover 43 is formed to fill excess space which would normally occur between cover plate 43 and member H and is provided with an extending lip 46 which is adapted to engage flange 32 of tubular member 30 and hold the same in the position shown in Figure 1.

Plate member l2, in combination with a casing 41 which is secured in sealed contact therewith by means of bolts 48 and gasket 49, constitutes a valve case 50, in which is m'ounted'an'inlet valve assembly 51 which is adapted to conduct fluid being drawn into pumping compartment l4 through valve assembly 5i which is also adapted to prevent counter-flow of liquid through it from said pumping compartment.

Chamber I3 is provided with outlet 53 which communicates with a cylinder 54 within which a reciprocating piston (not shown) is positioned I cylinder 18 to support diaphragm 15 against over expansion if valve 48 leaks while the pump is idle.

As will hereinafter more fully be explained the space l3 within casing I and outside ofthe diaphragm I is termed an impelling liquid chamber and the same is filled with liquid hereinafter called impelling liquid. Upon reciprocation of the piston within cylinder '54 imp'elling liquid is alternately drawn out of andtforced into the space l3 thereby creating'alternate suction and pressure pulsations therein, which in turn cause pumping compartment I l to alternately expand and draw in fluid being: pumped through valve case 50 and valve '51 and contract and expel said fluid through valve case 39 and valve '40.

As has more fully been pointed out in my United States Letters Patent No. 2,405,734, granted August 13, 1946, fora Pumping apparatus, on such strokes of the piston within cylinder 54 a small amount of air may be drawn into the impelling liquid compartment and ultimately this air seeks the highest point therein. Furthermore there is a certain leakage of fluid at the piston which actuates the impelling liquid. The above referred to copending application provides means to prevent air from accumulating'in the impelling liquid compartment and to replace liquid escaping therefrom.

During a period-of idlen-e'ssof the pump, leakage of fluid from pumping compartment 14 through inlet valve 5| may cause the inward displacement of diaphragm 15 from its normal position. If the piston in cylinder 54 is in position "to start on a pressure stroke after such leakage occurs,

diaphragm 15 may be completely'collapsed and, unless relief means are provided, it may be ruptured by being forced into the outlet conduit leading from compartment M on starting the pump.

1 have provided means whereby, if the diaphragm becomes so displaced, while the pump is idle, it will, when the pump is started, be relieved of excessive strain and be drawn into its normal locus of oscillation, said means consisting of means :adapted to prevent excessive entrance of liquid and to cause the admission o'f air into the impel- As shown more particularly in Figures 2 and 3, the aforementioned means are incorporated in the air and liquid inlet and outlet system shown generally at 56 and in the liquid inlet apparatus shown generally at 51.

Air inlet and outlet system 55 may briefly be described a follows:

Tubular conduit 60 communicates with passageway 6| in cylinder I0 and with the impelling liquid chamber [3. A threaded" casing 62 communicateswith and is supported at its upper end by conduit 60 and is adapted to permit the passage of fluid therethrough past an adjustable threaded member 63, mounted therein, to a conduit 65. Conduit 65 communicates with an en closed chamber 66 within which there is mounted a cup 61 in which the lower end of conduit 65 is mounted. Chamber 68 is provided with orifices 68 by which the same is vented to the atmosphere. Chamber 66 is also provided with outlet orifices 69 and 18, the former of which communicates with conduit H which leads through pet cock 12 from the bottom of chamber 6'6 to compartment 13 in tank 14. Outlet 10 communicates with conduit 15 which leads from a higher level in chamber 55 than does conduit H to compartment 16 of tank (4. 7

Cup 6? is adapted to receive liquid at a point near its bottom from the outletend of conduit 55 and to permit the overfl'ow'of said liquid into the surrounding space in chamber 35 at a higher level.

As shown more particularly in Figures 2 and 3 the liquid inlet system 51 comprises a cylindrical member which is provided with flanges 8| and 82 and is adapted to fit within orifice 83 in the wall of cylinder I8. It is secured to the wall of cylinder ID by means of bolts 84. A plate 85 closes the outer end of cylindrical member Bi! and is held in impervious relationship thereto as by means of bolts 86 and gasket 8'5.

A tubular member 88 is mounted within cylindrical member 80, co-axially therewith, and is provided with a flange 89 which; in turn, is provided with threads 98 which are adapted to cooperate with correspondingthreads 9'! in cylindr ica'l member 80. A threaded plate 9.2 closes the outer end of cylindrical member, '88 and is provlded with an orifice 93 adapted to receive push rod 94. Push rod 94 is provided at one end with a facing member 95 which is 'adapt'ed to contact the diaphragm I5, and a valve pallet 95 which within member [0. Orifice 83' is adapted to guide Push rod 94 as well as permit the flow of liquid therethrough. Plunger 98 is secured to the inner end of push rod 94 and engages a sprin 98 which is adapted to urge valve 96 toward the closed position shown in Figure2. Tubular member 88 is closed at its inner end by a plate lilil which is provided with an orifice I'M to which is secured a pinched rubber valve member I82 which is adapted to permitthe flow of liquid from within tubular member 88, and to prevent a counterflow of liquid through it into the same. Another and smaller orifice 103 is provided to permit the inflow and outflow of 'liquidfrom the space within tubular member 88 behind plunger 98.

Cylindrical member 88 is provided with another orifice I84 which permits the inflow and outflow of liquid from within that space within Tank" has previously beenmentioned herein. It comprises an outer supply compartment I3 and a smaller inner compartment I6 and is secured to the pump in any suitable manner and generally positioned below both the air'and liquid inlet and outlet system 56' and the liquid inlet system 51. I i

Tubular conduit H9 is fixed to the upper wall of tubular member 8% and is connected to a T- fitting III, one outlet of which is joined to conduit IIZ which terminates in a ball check valve device II 3 near the bottom of compartment 16. Ball check valve H3 is adapted to permit the flow of liquid into the space within tubular member 80 through conduit H2 but to prevent the outflow of liquid therefrom through said conduit. The other outlet of T-fltting II communicates with conduit II5 which leads through pet cock II6 into compartment I6. A restricted orifice device II! is placed within conduit II5 below pet cock H6 to cause resistance to the flow of fluid therethrough.

Compartment I6 is provided with an orifice I 29 on the wall thereof to provide communication between compartments 16 and I3 of tank M. A float I2I is provided in compartment I6 and is maintained in an aligned position over orifice I29 by a bracket I22 as shown. A valve member I23 is secured to the lower side of float I2I and is adapted to abut against the up-turned flange I24 around orifice I29 to provide a seal against the flow of liquid from compartment I3 into compartment I6 when the liquid level with- .in compartment I6 falls to such a level that valve pallet I23 and up-turned flange I24 are in contact.

The operation of the device may briefly be described as follows:

This may best be done by describing the'actions in the pump both under normal operating conditions and when it is stopped and later started after a period of idleness during which leakage has occurred.

Let it be assumed that the diaphragm I5 is in the position shown in Figure 1 and that all I cylinder 54 causes the withdrawal of liquid from the impelling liquid compartment I3 and creates a condition of suction in the pumping compartment I4, causing liquid to enter through valve case 59 and valve El and causing diaphragm I5 to assume the broken line position I5a shown in Figure 1. When the diaphragm is near the end of the suction stroke it engages disc 95 and causes rod 94 to move inward in tube 88, thereby opening valve 96 and permitting communication between the impelling liquid compartment and the interior of tubular member 69. Spring 99 is compressed and plunger 98 forces evacuation of a quantity of the liquid behind it through orifice I63 and valve I'02.,

Normally, since the diaphragm I5 engages disc 95 near the end of the suction stroke, when the velocity of the plunger of the pump is being decelerated at a high rate, the liquid in compart- :rnent I3 is under pressure when the valve 96 is open and no liquid is drawn into the impelling liquid compartment I3 during the balance of the suction stroke. However, during the'followlng pressure stroke, the diaphragm I5 moves away from the disc 95 but valve 96 is retarded in its closing due to the time required for the replacement of liquid previously expelled from that area behind plunger 98 through orifices I03 and I62. During this period the fluid being pumped is expelled from the pumping compartment I I through valve 46 and, concurrently, a small volume of liquid is expelled from impelling liquid compartment I3 through orifice 6|, conduit 60, and member 62. This liquid fills and over-flows the inner cup 61. The liquid overflowing inner cup 6! is divided, and one portion of essentially constant volume passes through conduit II into compartment I3. The balance passes through conduit I5 into compartment I6. On starting the following suction stroke valve 96 is not yet closed and liquid is drawn from the interior of cylinder 80 through orifice I04 and valve 96, into chamber I3 and a like volume of impelling liquid is drawn into cylinder 80 through valve I I3 and conduit I I2. A small quantity of liquid also enters the impelling liquid compartment I3 during the suction stroke from cup 61 through conduit 65, casing 62, conduit 66 and orifice 6I.

In such normal operation the outward limits of movement of diaphragm I5 is automatically established andremains constant at a location at which plunger 98 displaces a volume of liquid in the compartment behind the plunger 98, the return of which, through orifice I03, under the influence of spring 99 acting against the plunger 98, retards the closure of valve 96 just long enough for the volume of liquid being drawn from the compartment 16 into the pump to compensate for all liquid being lost to chamber I3 and not returned through the orifice 6I.

If, however, the pump is stopped and it happens that liquidis leaking out of the pumping compartment I4, as for example through inlet valve 5|, fluid in a compensating volume must enter the impelling liquid compartment I3 either through orifice 6|, valve 96, or cylinder 53.

Since the level of liquid within the cup 61' is higher than the level of liquid in tank 14, the

compensating fluid enters the impelling liquid compartment I3, preferentially through orifice 6I at a rate up to that at which resistance to flow in the resistance element 62 balances the pressure required to open valve II3 plus the difference between the hydrostatic pressure in the impelling liquid compartment I3 at the level of the liquid in cup 61 and in tank I6. Such compensating addition of fluid, if it is a liquid, in the impelling liquid compartment I3, creates a condition in the pump in which the pumping compartment I4 is V in a state of partial or total contraction whereas the plunger 54 of the pump is in a position to force a further and abnormal contraction of said compartment when the pump is started, and thereby to force the diaphragm' I5 into the member 36 and rupture it.

If, however, the compensating fluid being draw into the impelling liquidcompartment is air, the volume which may be expelled through orifice 6| and member 62 under a givenpressure is Very much greater than if it is liquid, and since the starting stroke of the pump is relatively slow it may be expelled without strain upon the diaphragm. I

One means which I have provided to cause the introduction of air instead of liquid under the above described condition is illustrated by cup p rases member 61 in combination with tube :65, in conjunction with'vents B8.

In operation this means functions as follows: Cup B1 fills and overflows during the pressure stroke .of the pump and is partly evacuated dur- 'ing the suction stroke. When the pump is stopped and slow leakage, as previously described, occurs from the impelled liquid compartment, cup 61 is very quickly emptied and thereafter air is drawn into the impelling liquid compartment through orifices '68, tube 65, member 62, tube 6i and mi fice 60. When the pump is started this air is forced out of the impelling liquid compartment through orifice BI and member 52 under moderate pre'ssureiand, it is found, all of the air will have been evacuated from the impelling liquid compartment after a few strokes of the pump and operation will become normal. If, however, the pump is stopped at the end of the suction stroke and a very fast leakage of the liquid from the impelled liquid compartment takes place, liquid is drawn into the impelling liquid compartment '53 by the Way of valve 96 before the latter has reached a closed position.

The other means suited to prevent an excessive admission of liquid into the impelling liquid compartment under the above described condition is illustrated in connection with small compartment 16 in supply tank M in which the orifice l2ii is provided for the entrance of an essentially coningly small. During operation the liquid ievel in compartment BB is not far below that in compartment l4 andduring normal operation float valve 12! remains completely open, but if, on stopping the pump, liquid is drawn through the ball valve 1 E3 in an excessive amount the liquid in chamber it falls and valve I23 closes to prevent the further admission of liquid into compartment '56 and air is subsequently drawn into the cylinder 38. When starting the pump the air so admitted into cylinder 8E! is ejected by opening the cock H6 or, if

constriction H7 is sufficiently narrow, cock i is be left open Without materially affecting the capacity of the pump.

In the event it becomes desirable to reduce the capacity of the pump, the same may be obtained by varying element 63 to permit an increased outflow of liquid from the impelling liquid compartment [3 and on the succeeding suction stroke to empty cup 61 and thereafter draw air through orifices 68, conduit 65 and orifice 6! into the impelling liquid compartment.

I claim:

1. In a pump having an expansible and contractable pumping compartment, an impelling liquid chamber and a diaphragm separating said compartment from said chamber, said diaphragm being adapted to pulsate in response to suction and pressure pulsations of liquid in said impelling liquid chamber, means adapted to admit air into said chamber under the influence of suction pulsations therein, said means including a hollow member adapted to receive liquid during the operation of the pump and to be evacuated of liquid prior to the admission of air into said chamber.

2. In a pump having an expansible and contractable pumping compartment, :an impelling liquid chamber, adiaphragm separating said compartment from saidchamber, and means adapted to prevent the admission of air into said chamber when the pump is in operation, and to admit air into said chamber under the influence of suction generated by the contraction of said compartment due to the outward leakage of liquid from said compartment when the pump is idle.

3. In a pump having an expansible and contractable pumping compartment, an impelling liquid chamber and a diaphragm separating said compartment from said chamber, said diaphragm being adapted to pulsa-te in response to suction and pressure pulsations of liquid therein and to cause successive periods of change in the volume of said'pumping compartment, means adapted to prevent the admission of air into said chamber when the pump is in operation and to admit air into said chamber under the influence of suction generated therein by the contraction of said compartment due to the outward leakage of liquid from said compartment when the pump is idle, said means including a hollow container adapted :to receive liquid during the operation of the pump and means adapted to function in lowering the level of the liquid in said container under the influence of said suction in said chamber and thereafter to function in admitting air into said rising a plurality of 'intercommunicating chambers adapted to contain impelling liquid, an expansibie and contractable pumping compartment and a diaphragm separating said compartment from said chambers, a conduit adapted to communicate said compartment with a source of fluid to be pumped, a valve adapted to prevent the outward passage of fluid from said compartment into said conduit, means adapted to admit air into at least one of said chambers under the influence of suction generated by the contraction of said compartment due to the outward leakage of liquid therefrom through said valve While the pump is not in operation.

5. In a pump of the character described comprising a plurality of intercommunicating chambers adapted to contain impelling liquid, an expansible and contractable compartment and a diaphragm separating said compartment from said chambers, a conduit adapted to communicate said compartment with a, source of fluid to be pumped, a valve adapted to prevent the outward passage of fluid from said compartment into said conduit, means adapted to admit air into at least one of said chambers during the period of contraction of said compartment due to the outward leakage from said compartment through said valve while the pump is not in operation, and means to admit a predetermined volume of water and an adjustably controlled volume of air into said chamber at each stroke of the pump.

6. In a pump having an expansible and contractable pumping compartment, a conduit adapted to communicate said compartment with a source of fluid to be pumped, an outwardly closing valve adapted to prevent the passage of fluid from said compartment into said conduit, an impelling liquid chamber and a diaphragm separating said compartment from said chamber, means adapted to admit air into said chamber under the influence of suction generated by the contraction of said compartment due to the 9 outward leakage of fluid from it through said valve, said means including a hollow member adapted to receive liquid during the operation of the pump and to be evacuated of said liquid prior to the admission of air into said chamber.

7. In a pump having an expansible and contractable pumping compartment, a conduit adapted to communicate said compartment with a source of fluid to be pumped, an outwardly closing valve adapted to prevent the passage of fluid from said compartment into said conduit, an impelling liquid chamber and a diaphragm separating said compartment from said chamber, means adapted to admit a controlled volume of liquid and air into said chamber under the influence of suction generated by the contraction of said compartment due to the outward leakage of fluid from it through said valve during a period when the pump is not in operation.

8. In a pump having an expansible and contractable pumping compartment, a conduit adapted to communicate said compartment with a source of fluid to be pumped, an outwardly closing valve adapted to prevent the passage of fluid from said compartment into said conduit, an impelling liquid chamber, a diaphragm separating said compartment from said chamber, and a plunger adapted to create, alternately, pressure and suction in said impelling liquid chamber,

means adapted to prevent the admission of air adapted to communicate said compartment with a source of fluid to be pumped, an outwardly closing valve adapted to prevent the passage of fluid from said compartment into said conduit, an impelling liquid chamber, a diaphragm separating said compartment from said chamber, and a plunger adapted to create, alternately, pressure and suction in said impelling liquid chamber, means adapted to prevent the admision of air into said chamber under the influence of suction created by the plunger while the pump is in operation, and to admit air into said chamber under the influence of suction in said chamber generated by the contraction of said compartment due to the leakage of fluid from it through said valve during a period when the pump is not in operation, said means including a hollow container adapted to receive liquid during the operation of the pump and means adapted to function in lowering the level of liquid in said container under the influence of suction in said chamber and thereafter to function in admitting air into said chamber under the influence of continued suction therein.

HARRISON S. COE.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Coe Aug. 13, 1946 

